help identifying makers mark on 18ct Pd ring

[4evabuying]

I have a diamond ring which is stamped with "18ct Pd". The Pd is stamped within a trapezium shape.
The ring is also stamped with a capital 'T' within a circle, which I am assuming is the makers mark. There are no other marks or stamps that I can see.
The ring is a trilogy ring (three diamonds) and is an older style, although I'm not sure if this is an old ring (ie: WWII when palladium was commonly used instead of platinum) or a reproduction of an older style ring, which is why I am hoping to find out who the maker is.
I believe that the ring was made in Great Britain or Australia (as in the US ring would have been marked 18k PD). Ring was given to me in 2008.
I would be grateful for any help identifying the makers mark.

[blackyoghurt13]

Well, you've helped me! I have a ring with the exact same 18ct, Pd in trapezium shape and a T in a circle. Mine is a bezel set diamond trilogy and definitely not a size T. I wonder if anyone could tell me any more about the history Thomas Jewellers? I can't find much info about them in any of my Australian jewellers books or online. They were established in Ballarat 1896 by founder James Thomas and then presumably handed down through the generations. I will have a look at the PROV but thought I'd see if little_closet has any local history they could share?